Platen-press



M. ROCKSTFIOH.

PLATEN PRESS.

APPLICATION.FILED OCT. 12, 1920.

Patented Dec. 27, 192 1.

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M. R0CKSTR0H.

PLATEN PRESS. APPLICATIOI} FILED OCT. 12 1920- I 1,401,818,. Patented Dec. 27, 1921.

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M. ROCKSTROH.

PLATEN PRESS.

APPLICATION FILED OCT. I2, 1920.

1,401, 1 Patented Dec. 27, 1921.

3 SHEETS-SHEET 3.

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Specification of Letters Patent.

Patented nee. 27, rear.

Application filed Qctoher 12, 182%. Serial No. 416,584.

To oZZ iii/tom it may concern:

Be it known that i, Max ROOKSTROH, manufacturer, a citizen of the German Republic, residing at Klein-Sedlitz, near Pirna,

Saxony, Germany, have invented certain new and useful improvements in Platon- Presses, (for which I have filed application in Germany on July 25, 1916,) of which the following is a specification.

Elly invention relates to platen presses provided with automatic devices for feeding and delivering the sheets of paper, and a primary object is to provide an improved olaten press of this type comprising various c'cviccs which are known in themselves, but are combined and arranged in an improved manner such that '"e. ious new ant considerably improved results are obtained. A novel feature of the invention is the combination of a rectilinearly reciprocating platen, several gripping devices'which are rotatable about the same and are actuated in such a manner that the rotation of a drum carrying the grippers begins exactly at the change of stroke of the platen independently of the position of the latter due to the regulator, and a device for opening and closing the grippers, by means of which the sheet is always caught in the same position of the platen relatively to the form independently ot the regulator.

Platen presses are well known, in which the gripping devices are led on endless belts over rollers around the platen and participate in the movement of the latter. in

these devices the sheet is fed directly to the grippers, the fixed parts of the grippers be ing provided with marks, against which the sheet is pressed by the conveying means on the laying-on board and is seized by the grippers when the stroke or" the platen change The change or" strokeoi the platen in the open position does not, however, al.-

ways take place in the same position relatively to the laying-on board in platen presses having a movable platen. This is due to the pressure being adjusted bythe eccentrics on the shaft of the platen to an amount which varies 'with each kind of work. The greater the eccentricity of the eccentrics the nearer the grippers approach to the laying-on board when the stroke changes. The grippers are nearest to it when the pressure is entirely absent. The grippers are opened and closed by adevicc which always exercises a constant of:

feet with regard to the main cranks whereby the grippers are closed, however in various positions of the platen. Insome cases the sheet is gripped earlier and in others later, according to the position of the pressure regulator. As thesheet is pressed by the conveying means against the marks in the gripping devices, it also has to participate in the differences in the end position of the grippers. Consequently, in one position otthe regulator it will exactly reach the marks, while in another position the marks have to press the sheet back. As this 1 movement takes place in a direction contrary to the direction of motion oi": the con veying means, if the paper is thin the sheets will consequently be crumpled. Further, such gripping devices provided with marks have to be made very accurately and exactly alike, and must be provided with an arrestmg device in the removing and printing position, in order to obtain exact register; Owing to the gripping devices being guided over rollers, when the sheet is being conveyed to the place, where it. is printed and laid off it has to be sharply bent, which,however, is a disadvantage when the paper is thick.

Platen presses having revolving gripping devices are also known. 7 These comprise a fixed platen, however, so that the layingon board must be arranged far below the platen which renders the adjustment of. the marks and the, like very dificult and the feed of the sheets not easily observed. Also, these printing presses have no parallel end movement of the platen for effecting the printing. Consequently, no work for which such parallel movement is a preliminary condition'can be, done on these presses.

Further, platen presses are known in which grippers arranged at the lower edge of the platen withdraw the sheet, when swinging into position for the impression, from' a laying-0n board located above the platen the arrangement being such that the grippers always close at the same place. This kind of feed of the sheets, however, has the great detect that the sheet is brought from above onto the platen, which readily sheet when the @ne illustrative embodiment of the invention is d'agrammatically represented by way. of example in the accompanying drawings, wherein:

Figure 1 is a side elevation, partly in section, showing part of my improved platen press comprising a rectil nearly reciprocated feeding and delivering device, the grippers being shown in open position.

Fig. 2 is a view similar to T g. 1, the grippers being shown as closed and on'the to the printing position.

Fig. 3 is a view similarto Figs. 1 and 2, the grippers be ng shown in the printing position, and

Fig. i is a front end elevation of the Press, the parts being in the same position as shown in 3;

Fig. 5 is a side elevation showing the feed mechan sm for the grippers when the platen s in the printing position, and

Fig. 6 is a view similar to Fig. 5, the parts being shown in the position assumed shortly before the platen is in its open position.

Referring to the drawings, the bed 1 has eyes 2 and 3 in which are mounted rectilinear guides, in the embodiment round rods 1, which are disposed at right angles to the bed, and on which the platen 5 is guided. This platen has side walls 6 and 7, which have lugs 8 and 9 guided by the rods 1, and it has bearings 10, on which rings 11 are rotatable. These rings are connected together by members 12 which together constitute a drum. The members 12 each has a gripping device associated tierewith and they are turned or switched in such a man nor that one gripping device is always ready for taking a'sheet from the laying-on board 20. The connecting members 12 have parts formed as lower jaws 13, and have bosses 11 for carryin the gripper rods 15 and the upper jaws 19. These rods carry levers 16 having antifriction rollers 17 which are used for actuating the jaws 19 and thereby opening the grippers. The lay-- ing-on board 20 is arranged at the endof the path of the platen. The sheet is laid by hand or mechanically on the layingon board 20 or on conveying means 18 provided at the latter, and is pushed against the marks 2]. provided at the lower end thereof, where it is adjusted. For withdrawing the sheet from the board or other means the platen is driven to the right along the rods 4 by means of cranks 22 which are connected with the shaft 2 1 of the platen by rods 23. Before the platen arrives at its outer end position the roller 17 runs onto the tripping member 27 which is fulcrumed at 26 and is held in its normal position by a counterweight 28, whereby the member 27 is rocked and the grippers are opened. As the platen moves farther outward the roller 17 leaves the member 27, the latter rocks back into its normal position and the roller rolls on the inclined way 25. On the return stroke of the cranks 22 the roller 17 rolls back down the inclined way 25, whereby the grippers 19 always close and seize the sheet at the same place. At the same time the marks 21 are lowered and the rings 11 are turned in the manner described hereinafter, and the sheet is conveyed onto the platen.

1n the embodiment shown, the drum 11, 12 is turned by means of a lever 31 (Figs. 5 and 6) which is mounted to swing about the shaft 2-1 of the platen and is driven by means of toothed segments 31, 33 and an arm 33', on the latter carryingan antifriction roller -11 running in a curved way 11 formed in a bracket 32 carried by the bed 1. The lever 31 carries a belt or latch 35 whose wedge-shaped end 36 can take into wedge shaped recesses 38 in the ring 11. The bolt or latch 35 carries a laterally extending pin 10, and a spring 37 arranged between the pin 40 and an abutment formed on or carried by the lever 31 tends to draw the latch 35 inwardly; that is to say, toward the shaft 3 1, so as to cause the wedge-shaped end of the bolt or latch 35 to enter or snap into the notches 38 of the ring 11 when said wedge-shaped end arrives opposite said notches. The wedge-shape of the end of the latch which drives the ring isparticularly suitable because, although the angle of oscillation ofthe lever 31 will vary according to the printing position at the time, the ring 11 can be evenly driven by the lever 31. The shape and arrangement of the curved way 11 cause any difference in the magnitude of the swing of the lever to be evident only in the open position of the platen, that is to say only at the commencement of the feed movement of the love" the result being that when the amplitude of swing of the lever 31 is small, the wedge enters only a short distance into the recess 38, while when the swing of the lever is larger the wedge enters a greater distance into said recess. In order that the ring shall not be turned varying distances, l arrange that, in

the course of the turning of the ring, the wedge is positively drawn entirely into the recess 38, so that the position of the lever 81 relatively to the ring 11 is always the same toward the endof the turning move ment of the rin 7 To this end '1 provide a spring actuated hoolr 39 which is mounted to swing on a pivot arranged eccentrically to the shaft 24 of the platen as well as to the center of oscillation of the lever 81. When the ring begins to turn, after the latch 35 has snapped into a recess 38 the hook 39 takes over the pin 40 on the latch and, owing to its eccentric position, pulls the latch home into the recess. Shortly before the end of the return movement of the lever the hook abuts against a fixedly mounted stop 44- which arrests it and disengages it from'the pin 40 so that the latch 35 may be disengaged from the recess 38 in the ring. This isbrought about by means of a slide 45 which is mounted .to reciprocate on the platen which is engaged and actuated by fixed stops 4C6 an-c 4-! carried by the'platen. In the position shown in Fig. 5 the slide 45 has been moved over into its outer-position and the latch has been removed from the recess. In the position shown in Fig. 6 the slide 45 has not yet reached its inner end position. An

' important function of the slide 45 is that it firmly locks the ring while it is stationary and thereby insures correct registration in the printing. lhe grippers are opened and the sheet is delivered-to the table l9 when the roller 17 coacts with the fiXGCl'StOP 48. lVhen this occurs the sheets fall out of the opened grippers into the table.

Owing to the cen rifugal motion of the grippers the paper or board to be printed is drawn around the platen in a curve corresponding in size to the circle, so that bending the sheet about an arc of short radius is avoided and thick paper, or even board, can be fed and delivered.

By holding the rocking member 27 in the position shown in Fig. 1, the grippers can be put out of action, because the roller 17' will then roll back over the member 27 and the grippers will remain open. i

Instead of the above described dev1ce for closing the grippers any other may be used if it closes them exactly at the same place from the spirit or" my invention.

I claim:

l. in a platen press, the combination with a platen and means for rectilinearly reciprocating the same, of a plurality oi:

gripping devices mounted about the platen,

2. In a platen press, the combination with a platen, means for rectilinearly actuating said platen, a drum vrotatable aboutsaid platen comprising spaced rings connected by transverse rods, grippers mounted upon said I drum and cooperating means on said platen and drum for rotating said drum through the motion of said platen; V

3. In a platen press, the combination with a platen, a shaft carried thereby, and means connected withvthe shaft for rectilinearlyreiprocatin'g the platen into its open and closed positions, of rings mounted to rotate about the platen, rods connecting ther'ings together, said-rings and rods constituting a drum, grippers mounted on said drum, a lever mounted to swing about said shaltand adapted to engage with said drum, positively guided driving means mounted on the platen and geared with said lever for rotating the drum, the commencement of the rotation of the drum coinciding exactlywith the change of stroke of the platen independently of the posit-ion of the platen, and means for 010s ing the grippers in a predetermined position of the platen,substantiallyas described.

4. In'aplaten press, the combination with a bed, a platen mounted thereon,'ashaft carried by the platen, and means for rectilinearly reciprocating the platen into its open and closed position, of a drum mounted to rotate about the platen, grippers mounted on the drum, a lever mounted to swing about said shaft and adapted to engage'with and be disconnected from the drum, a curved guide on the bed, a toothed driving member pivoted on the platen, meshing with the lever and positively guided by said guide, the shape of said uide being such that the commencement of rotation of the'drum coincides exactly with the change of strokeoi 7 the platen independently'oi the position of the platen, and means for closing the grips pers during rotation of the same, substantially as described. 1

5. In a platen press, the combination with a bed having an inclined way,'a platen mounted to slide on the bed and means for rectilinearly reciprocating the platen, of

rings mounted to rotate about the platen, a plurality of grippers mounted on the rings, each gripper comprising a fixed jaw and a movable jaw having a driving arm, and a tripping member mounted to-rocl; on the bed and adapted to coact with the driving arm of a gripper moving rectilinearly into end .op--

erative position, and thereby open the gripl driving arm normally sliding down 'aid incline-a Way and closing the gripper n other direction adjacent ll-FGM), substantially as described.

6. in a platen press the combination of a d having inclined Way, a platen mountrectilinearly on the bed, a layingnember located adjacent to said inclined rings mounted to rotate about the a l lnrality of grippers mounted on the rings, means for reciprocating the platen driving a gripper to and "from the layng-on member, eaelngripper cornnrising a ired aw and a IIlOVilblG aw having a driving arm, a tripping tivonrmed member, having Weight on one arm mounted to rock on the ing arm of a grieper moving toward the laying-on member and thereby open the eer, the driving-arm moving into the inclined Way on leaving the trinping member closed position, of a ring having Wedgeshaped recesses mounted to rotate about the laten, grippers mounted on the ring, a lever mount d to SWli'lg about said shaft, a

bed and'adaited to coact with the drivia-oneie spring-pressed latch having a Wedge-shaped end carried by the lever and adapted to take into said recesses, means mounted eccentrically on the shaft for positively drawing the latch into said recess, driving means mounted on the platen and geared with said lever for rotating the ring, and means for closing the rippers in a predetermined position 0.2? the p aten, substantially as described.

8. In a platen press, the combination of a led having two stops mounted thereon, a platen mounted to reciprocate rectilinearly on the bed, a shaft carried by the platen, means connected With the shaft for driving the platen into its open and closed positions, a ring havingrecesses mounted to rotate about the platen, grippers mounted on the ring, a lever mounted to swing about said shaft, a springpressed latch carried by the lever for taking int the recesses and thereby connecting the lever with the ring, driving means mounted on the platen and geared with said lever for rotating the ring, a slide mounted on the bed and adapted to coact With said stops and to take into and be reroved from said recesses thereby intermittently lock the ring, and means for closing the grippers in a predetermined position of the platen, substantially as described,

in testimony whereof l havehereunto set my hand in presence of two subscribing witnesses.

MAX ROCKSTROH. l Vitnesses l/VoLDEMAR BORING, KARL WEBER. 

